Multicellular Organisms First Appear

Q5: Sexual reproduction probably evolved<br>A)to increase genetic variation.<br>B)to

Q6: At the time the earth was formed,the

Q7: The mass extinction of 65 million years

Q8: Most of the history of life on

Q9: The universe<br>A)has always been the same size

Q11: The sudden appearance of organisms with shells

Q12: Photosynthesis is<br>A)a process found only among modern

Q13: Organic compounds on earth first came from<br>A)processes

Q14: The formation of the "supercontinent" of Pangea<br>A)was

Q15: How old is the first evidence of